BLAES, Omer, Eva ŠRÁMKOVÁ, Marek ABRAMOWICZ, Wlodel KLUZNIAK and Ulf TORKELSSON. Epicyclic oscillations of fluid bodies: Newtonian nonslender torus. Astrophysical Journal. CHICAGO: UNIV CHICAGO PRESS, 2007, vol. 665, No 1, p. 642-653. ISSN 0004-637X. Available from: https://dx.doi.org/10.1086/519782.
Other formats:   BibTeX LaTeX RIS
Basic information
Original name Epicyclic oscillations of fluid bodies: Newtonian nonslender torus
Authors BLAES, Omer, Eva ŠRÁMKOVÁ, Marek ABRAMOWICZ, Wlodel KLUZNIAK and Ulf TORKELSSON.
Edition Astrophysical Journal, CHICAGO, UNIV CHICAGO PRESS, 2007, 0004-637X.
Other information
Original language English
Type of outcome Article in a journal
Confidentiality degree is not subject to a state or trade secret
Organization unit Faculty of Philosophy and Science in Opava
Doi http://dx.doi.org/10.1086/519782
UT WoS 000248675700047
Keywords in English accretion, accretion disks; black hole physics; hydrodynamics; X-rays : binaries
Tags clanek, LC06014, MSM4781305903, Torokcentrum
Changed by Changed by: RNDr. Kateřina Klimovičová, Ph.D., učo 10653. Changed: 12/4/2021 14:17.
Abstract
We study epicyclic oscillations of fluid tori around black holes ( in the Paczynski-Wiita potential) and derive exact analytic expressions for their radial and vertical eigenfrequencies V-r and V-z to second-order accuracy in the width of the torus. We prove that pressure effects make the eigenfrequencies smaller than those for free particles. However, the particular ratio V-z/V-r = 3/2, which is important for the theory of high-frequency quasi-periodic oscillations (QPOs), occurs when the fluid tori epicyclic frequencies V-r and V-z are about 15% higher than the ones corresponding to free particles. Our results therefore suggest that previous estimates of black hole spins from QPOs have produced values that are too high.
PrintDisplayed: 20/7/2024 16:16